GulagDB::get_where_clause_from_filters() implements jqgrid-style search filtering

app/Gulag.py

@@ -59,7 +59,7 @@ class Gulag:
     for arg in args:
       if(arg == 'query_offset' or arg == 'query_limit'
          or arg == 'sort_index' or arg == 'sort_order'
-         or arg == 'rfc822_message'):
+         or arg == 'rfc822_message' or arg == 'filters'):
         continue
       if arg not in self.fields[fields_target]:
         raise GulagException(
@@ -229,7 +229,7 @@ class Gulag:
       ) from e
     if 'rfc822_message' not in args:
       return qms_db
-    # recognise all IMAP mailboxes to read from
+    # recognize all IMAP mailboxes to read from
     mailboxes = {}
     for qm in qms_db:
       if qm['mailbox_id'] not in mailboxes:

app/GulagDB.py

@@ -5,6 +5,7 @@ from Entities import(
   AttachmentException,URI,URIException
 )
 from GulagUtils import whoami
+import json
 
 class GulagDBException(Exception):
   message = None
@@ -14,6 +15,7 @@ class GulagDBException(Exception):
 class GulagDB:
   conn = None
   uri_prefixes = None
+  vcols = None
 
   def __init__(self, args, uri_prefixes):
     try:
@@ -34,6 +36,9 @@ class GulagDB:
           autocommit=True
         )
       self.uri_prefixes = uri_prefixes
+      # virtual columns cannot not be stated in where-clause
+      self.vcols['attach_count'] = {}
+      self.vcols['uri_count'] = {}
     except mariadb.Error as e:
       raise GulagDBException(whoami(self) + str(e)) from e
 
@@ -94,16 +99,43 @@ class GulagDB:
          or arg == 'rfc822_message'):
         continue
       if(cnt == 0):
+        if arg in self.vcols:
+          where_clause += "having " + arg + "='" + args[arg] + "' "
+        else:
           where_clause += "where " + arg + "='" + args[arg] + "' "
       else:
         where_clause += "and " + arg + "='" + args[arg] + "' "
       cnt += 1
     return where_clause
 
-  def parse_filters(self,filters):
-    # TODO
-    # {"groupOp":"AND","rules":[{"field":"Customer","op":"eq","data":"eosp"}]}
-    return True
+def get_where_clause_from_filters(self,filters_json):
+  # {"groupOp":"AND","rules":[{"field":"available","op":"eq","data":"true"}]}
+  filters = None
+  where_clause = ""
+  try:
+    filters = json.loads(filters_json)
+  except json.JSONDecodeError as e:
+    raise GulagDBException(whoami(self) + "JSON parse error: " + e.msg) from e
+  for rule in filters['rules']:
+    field_op_data = None
+    if(rule['op'] == 'eq'):
+      field_op_data = rule['field'] + "='" + rule['data'] + "'"
+    elif(rule['op'] == 'bw'):
+      field_op_data =  rule['field'] + " like '" + rule['data'] + "%'"
+    elif(rule['op'] == 'ew'):
+      field_op_data = rule['field'] + " like '%" + rule['data'] + "'"
+    elif(rule['op'] == 'cn'):
+      field_op_data = rule['field'] + " like '%" + rule['data'] + "%'"
+    if(field_op_data == None):
+      raise GulagDBException(whoami(self) + "invalid rule-op: " + rule['op'])
+    if(len(filters['rules']) == 1 or len(where_clause) == 0):
+      if rule['field'] in self.vcols:
+        where_clause = "having " + field_op_data
+      else:
+        where_clause = "where " + field_op_data
+    else:
+      where_clause += " " + filters['groupOp'] + " " + field_op_data
+  return where_clause
 
   def get_mailboxes(self):
     try:
@@ -183,13 +215,18 @@ class GulagDB:
       raise GulagDBException(whoami(self) + str(e)) from e
 
   def get_quarmails(self,args):
+    where_clause = ""
+    if 'filters' in args:
+      where_clause = self.get_where_clause_from_filters(args['filters'])
+    else:
+      where_clause = self.get_where_clause(args)
     try:
       cursor = self.conn.cursor()
       query = "select *,(select count(*) from QuarMail2Attachment"
       query += " where QuarMails.id=QuarMail2Attachment.quarmail_id) as attach_count,"
       query += " (select count(*) from QuarMail2URI"
       query += " where QuarMails.id=QuarMail2URI.quarmail_id) as uri_count"
-      query += " from QuarMails " + self.get_where_clause(args)
+      query += " from QuarMails " + where_clause
       query += " " + self.get_limit_clause(args) + " ;"
       cursor.execute(query)
       results = []
@@ -463,4 +500,3 @@ class GulagDB:
         raise GulagDBException(whoami(self) + str(e)) from e
     cursor.close()
     return True
-